.shadow {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.2);
}

.center {
  width: 400px;
  height: 250px;
  background: #fff;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  padding: 20px;
}

header {
  height: 40px;
  border-bottom: 1px solid #777;
  font-size: 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
